For which of the following situations is a missed approach procedure necessary?

A missed approach procedure is necessary primarily in situations where a safe landing cannot be completed, which particularly applies to the scenario where visual references are lost during a standard approach. This scenario highlights the importance of maintaining situational awareness and safety; if the pilot can no longer see the runway or other visual cues essential for landing, it is prudent to initiate a missed approach to prevent potential accidents.

In the context of missed approach protocols, these procedures are designed to ensure that pilots have clear guidelines to follow when they cannot land as planned, which would include instances of bad weather or other visibility issues. This procedure typically involves climbing to a specified altitude, following a designated course, and awaiting further instructions from air traffic control.

While establishing a new flight plan and not obtaining clearances to land can lead to decisions regarding approach, these actions do not inherently necessitate a missed approach procedure in the same way that losing visual references during an approach does. Therefore, the nature of the situation where visual references are lost directly correlates with the need for a missed approach process to ensure safety.